Various transition metal and transition metal oxide catalysts have been used for electrochemical carbon dioxide conversion. Among them, copper is known as the only transition metal element capable of converting carbon dioxide into a C2+ material with relatively high efficiency. Although there are many research results supporting the reason for the efficient generation of C2+ products when copper oxide is used as a carbon dioxide conversion catalyst, a clear mechanism theory has not been established, and there are many controversies such as differences of opinion. However, the most accepted research result is that the efficiency of the product varies depending on the oxidation state of copper in the carbon dioxide conversion process, and through the optimal oxidation state control, the catalyst has the optimal binding energy to produce a product of C2+ or higher. We control the oxidation state of copper through N plasma treatment and use it for electrochemical carbon dioxide conversion. By treating the synthesized CuO nano rod particles with N plasma, as a result, the number of catalytic reaction sites was increased according to the interlayer formation. In addition, a positive effect on the electrochemical carbon dioxide conversion reaction according to N doping was also confirmed. We increased the sites participating in the catalytic reaction by creating an interlayer on copper oxide using plasma. At the same time, by doping N into the interlayer, high C2+ product faradaic efficiency was achieved. The method of forming the interlayer while reducing copper oxide using only N plasma was found to have a negative effect on the generation of C2+ products by reducing the copper oxide to the copper state. We solved this problem, and In addition, higher C2+ efficiency could be obtained compared to pristine CuO by doping N through N plasma in the additionally generated interlayer. As far as we know, studies of doping N using plasma have been reported, but studies using doped N for electrochemical carbon dioxide conversion while forming an interlayer as in this study have not been reported. With the novel method, it was possible to achieve C2+ faradaic efficiencies of more than 70% through electrochemical carbon dioxide conversion.

Nitrogen induced interlayer on CuO nanorod for electrochemical CO2 reduction to C2+ product

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.